compat: backport definition of PCI_MSIX_ENTRY_CTRL_MASKBIT

compat: backport definition of PCI_MSIX_ENTRY_CTRL_MASKBIT

This backports the addition of PCI_MSIX_ENTRY_CTRL_MASKBIT.

mcgrof@frijol ~/linux-next (git::master)$ git describe --contains 8d805286968811223cca002134ba3d81244d5313
v2.6.38-rc1~55^2~14

commit 8d805286968811223cca002134ba3d81244d5313
Author: Sheng Yang <sheng@linux.intel.com>
Date:   Thu Nov 11 15:46:55 2010 +0800

    PCI: Add mask bit definition for MSI-X table

    Then we can use it instead of magic number 1.

    Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
    Cc: Matthew Wilcox <willy@linux.intel.com>
    Signed-off-by: Sheng Yang <sheng@linux.intel.com>
    Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>